| Project/Area Number |
15590208
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental physiology (including Physical medicine and Nutritional physiology)
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| Research Institution | Nara Women's University |
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Principal Investigator |
MORIMOTO Keiko Nara Women's Univ., Environmental Health, Prof., 生活環境学部, 教授 (30220081)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAMATA Akira Nara Women's Univ., Environmental Health, Assoc.Prof., 生活環境学部, 助教授 (00264755)
YOSHIDA Ken-ichi Tokyo Univ., Graduate School of Med., Prof., 大学院・医学系研究科, 教授 (40166947)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2004: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2003: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | psychological stress / estrogen / blood pressure / catecholamine / endothelial nitric oxide synthase / telemetry system / postmenopausal women / menstrual cycle / ノルエピネフリン / 4-hydrixy-2-nonenal / ハンドグリップ / 一酸化窒素 / 心拍数 / 末梢血管 |
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| Research Abstract |
We obtained the following results on the effect of estrogen on stress-induced pressor responses and its mechanism.
(1)Estrogen attenuates pressor responses induced by psychological stresses through endothelial nitric oxide synthase(eNOS) overexpression in rats.
Pressor response to the cage-switch stress tended to be suppressed in the female (F) group compared with the male (M) group in free moving rats using the telemetry system. Furthermore, these responses to the cage-switch and restraint stresses were attenuated significantly in the ovariectomized estrogen-treated (E) group compared with the placebo-treated (P) group. However, pretreatment of NOS inhibitor diminished the difference of the stress-induced pressor response between the P and E groups. Moreover, the expression of eNOS in the mesentery enhanced significantly in the E group compared with the M and P groups. These results suggest that estrogen attenuates psychological stress-induced pressor responses and the mesenteric eNOS overexpression could explain the mechanism for its effect in rats.
(2)Pressor response to mental stress varies during menstrual cycle depending on plasma estradiol levels in women.
The resting blood pressure(BP) was not different between the menstrual (M) and the pre-ovulatory (O) phases of menstrual cycle in young women(YW). The elevations of systolic BP(SBP) and diastolic BP(DBF) induced by the Color Word Test(CWT) were slightly, but not significantly attenuated in O-phase compared with M-phase. In addition, the resting plasma norepinephrine(NE) was higher in O-phase, and its CWT-induced elevation tended to be attenuated in O-phase. Furthermore, the resting DBF was higher in postmenopausal women(PM) than YW. The significant and immediate elevation of DBP during the CWT was greater in PM than in YW and continued until about 15 min of the recovery period. These findings suggest that estrogen may attenuate the DBP elevations induced by the mental stress in women.
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